Factors associated with depressive symptoms in uncontrolled asthmatics

Recent epidemiological data indicate that approximately 6.7% of US adults suffer from depression in any given year. The purpose of the study is to identify factors associated with depressive symptoms in a large diverse group of patients with poorly controlled asthma. The factors include quality of life (QOL), lung function, asthma knowledge, attitudes, self-efficacy, symptoms and control of disease.

Baseline characteristics of a cohort of 599 subjects with asthma recruited from twenty Asthma Clinical Research Centers across the United States were examined. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to stratify subjects into those with depressive symptoms (CES-D score ≥ 16) and those without depressive symptoms (CES-D < 16). Bivariate statistics were used to compare the two groups; additionally, logistic regression was used to determine factors that have the greatest association with depressive symptoms.

Subjects with depressive symptoms had significantly lower QOL scores and less knowledge about their disease than subjects with no depression; however, lung function (FEV1%) and asthma control were not significantly associated with depressive symptoms in the logistic regression analysis. Subjects who were non-white had lower household income, high school diploma or less, and those who were unemployed or disabled had significantly higher scores for depressive symptoms.

Subjects with depressive symptoms have significantly less knowledge of their disease and poorer QOL compared to those without depressive symptoms. Evaluating depressive symptoms in subjects with asthma will provide a more complete picture of their overall condition. The role of asthma education on depressive symptoms in this population needs to be further investigated. The effect of QOL on treating depression in asthma patients also needs to be studied.